Tomato cones--tall, cylindrical frames designed to support growing tomato plants--are available in sizes to fit different varieties of tomatoes. Typically, the cones are made of galvanized and welded steel. Used properly, these supports conserve space in the garden by encouraging tomato plants to grow vertically. As an added benefit, plants grown in tomato cones produce more fruit because they are protected from ground-dwelling pests like slugs and rabbits, experience fewer fungal diseases and receive better air circulation.
Purchase your tomato cones based on the predicted size of your plants. For determinate, bush-type plants, a 24- to 36-inch-tall cone is adequate. For larger, indeterminate tomato plants, look for 36- to 72-inch cones.
Lower the cone gently over the plant and push the legs as deeply into the soil as possible. The bottom ring of the cone should contact the soil. Tap the bottom ring with a rubber mallet to help set the legs as firmly as possible.
Add four 6-inch-long landscape staples around the perimeter of the bottom ring for stability. Landscape staples are U-shaped metal pins commonly used to hold landscaping fabric or sod in place. You can also substitute tent stakes or homemade staples using 12-inch lengths of 8-gauge wire. Bend the wire in half and insert it over the bottom ring of the cone, pressing deeply into the soil.
Train the plant to stay inside the cone during the first month of growth. Use soft twine or strips of fabric to secure the vine to the inside of the cage.
Support the growing fruit. As the plants begin to set fruit, tie the vines to the nearest horizontal ring. Tie the vine loosely, approximately 2 to 3 inches from the blossom end. Do not force the vine or bend it sharply, which will weaken the stem, leaving it vulnerable to breakage as the fruit grows and becomes heavy.
Turn the ends of the vines inside the cone as the plant grows. To prevent crowding and promote ripening, prune branches regularly to maintain three or four main fruiting branches.